This invention relates to beam supply devices for supplying proton beams, heavy particles beams, etc., to devices which utilizes such beams, such as cancer therapy equipment and experimental radiation apparatus.
FIG. 5 is a cut-away perspective view of a conventional beam supply device. The beam (e.g., a proton beam or a heavy particle beam) generated by the beam generation device 1 (e.g., a synchrotron) is guided to the branch point by means of a pre-branching beam transportation device 2. At the branch point is disposed a branching deflection electromagnet 11a, which, when excited, generates a magnetic field for deflecting the beam by means of the Lorentz force. If the branching deflection electromagnet 11a is not excited and the interpole magnetic field thereof is null, the Lorentz force does not act upon the beam and the beam proceeds straight into a beam transportation device 12a and is guided horizontally into a beam utilization room 5a in front of the beam generation device 1. On the other hand, when the deflection electromagnets 11a and 11b are excited, the beam is first deflected upward by the branching deflection electromagnet 11a and then horizontally by the deflection electromagnet 11b, the beam being guided through the beam transportation device 12b, which may be a pre-branching type beam transportation device. If the branching deflection electromagnet 11c is excited, the beam is further deflected downward, guided through a beam transportation device 12c, and led into the beam utilization room 5a. On the other hand, if the branching deflection electromagnet 11c is not excited, the beam proceeds straight through a beam transportation device 12d. The beam is further deflected by an excited deflection electromagnet 11d, guided through the vertical extension of the beam transportation device 12d, and thence led into a beam utilization room 5b which is situated on the downstream side of the beam utilization room 5a.
The conventional beam supply device of FIG. 5 has the following disadvantage. The arrangement requires as many beam transportation devices as there are beam orbits leading into the beam utilization rooms. The beam transportation devices are expensive. If a large number of the beam utilization rooms must be provided, or a number of beam incident angles must be provided for each beam utilization room, the overall installation cost of the beam supply device becomes substantial.